I think it's a product of Imperial Glass (Bellaire, Ohio, USA), specifically their No. 188 footed ivy ball. They called this Early American Hobnail and made opalescent items in the early 1930s. Duncan Miller (Washington, Pennsylvania USA) made a similar item, and their catalogs mention a 5" tall version.

Hi JamesThanks so much for the information. When I entered it into the Bing search engine here's the results I found in Worthpoint:

Depression Uranium OpalescentImperial glass co. "Early American Hobnail" Green Opalescent Footed Ivy Ball Vase Non-Iridescent Measures: alittle over 6 inches tall. This lovely Green Ivy Ball Vase opalescent and has a round footed base with a ball stem, the pattern that covers the ivy ball vase is called " Early American Hobnail" also known as " Dewdrops". The vase was made from Imperial glass co. in 1932, it is shown in the Marie Hazel Weatherman book 2 Colored glassware of the Depression era. on page 151 and 152. This Hobnail can be confused with the Duncan and Miller Early American Hobnail, they are both very similar. T is No Imperial Logo! Non-Iridescent This Ivy Ball Vase is green and due to the year of make it does contain traces of uranium and does glow under a black light!

The picture of the ivy ball in Worthpoint is the same as mine. You hit that on the nail and saved me so much time which is greatly appreciated!!Have a wonderful holidayMarie